Mokuba Kaiba's Unremarkable Collection of Mundane Moments
by fearowkenya
Summary: Snapshots of the Kaiba brothers doing really normal things in the midst of their very unusual lives. In the latest chapter: Mokuba decides he wants to try drinking coffee. Seto doesn't understand why. Crossposted from AO3.
1. Mokuba Kaiba Makes a Dreadful Decision

**Chapter Summary:** Mokuba Kaiba is lactose intolerant and makes a very poor decision.

 **Author's Notes:** since i am a person cursed with food allergies, and i have friends who are cursed with seasonal allergies, sometimes we get together and headcanon jam about our favorite characters having allergies so that we can relate. and thus, lactose intolerant mokuba was born.

* * *

 **Mokuba Kaiba's Unremarkable Collection of Mundane Moments**

 **Chapter 1:** Mokuba Kaiba Makes a Dreadful Decision

The second the door to his study creaked open, Seto was able to recognize the sound of a metal spoon scraping against a cardboard container, a tell-tale sign that his little brother was doing something _incredibly_ _stupid_.

"Hi, nii-sama!" his younger brother chirped. Seto could see the spoon hanging out of his mouth from the corner of his eye.

"Mokuba," he said, without even looking away from the computer screen, "You'd better not be eating what I think you're eating."

"Wow, good morning to you too," Mokuba said. Seto could hear the spoon clink against his teeth as he spoke.

The younger Kaiba plopped into the extra rolling chair by the window, shoving another spoonful of ice cream into his mouth. Then another. And another.

Seto stopped typing. "Mokuba, you are going to be sick. Furthermore, why are you eating _ice cream_ for _breakfast_?"

"Oh, like you're one to talk," he tapped the spoon against the side of the container, "You don't even _eat_ breakfast. You wouldn't eat _at all_ if I wasn't here to remind you."

"Yes I would."

"Nii-sama, please."

Seto turned his attention back to his computer screen, and Mokuba smirked, taking his older brother's silence as a victory. They stayed quiet for a while longer, the spoon against the bottom of the ice cream container the only sound breaking the stillness. One minute passed. Five minutes. Ten.

Seto looked up from the computer screen for the first time all morning. "How much of that have you eaten?"

Mokuba shrugged, leaning against the back of the chair, spoon hanging out of his mouth again.

"That container was full yesterday."

He shrugged again.

"Did you even take your lactase tablets first?"

The chair rotated gently, turning the younger Kaiba away from his brother.

 _"Mokuba."_

He let the chair spin slowly until he was facing Seto again. "Oh, c'mon, nii-sama, I'll be _fine_ ," he said with a wave of his hand. He tapped his foot on the ground to keep the chair turning.

Seto sighed and shifted his focus back to his computer. "All right. Suit yourself."

* * *

 _"Ughhhhh..."_

Seto glanced up at the sound, looking over to where his brother lay on the floor, clutching his aching stomach. The younger Kaiba was sprawled out on the carpet, gazing mournfully at the ceiling. The chair sat abandoned by the window, still spinning ever so slightly.

 _"Ughhhhhhhhh…"_

Seto looked back to the computer screen. "I hope you don't plan on lying on my floor all day."

Mokuba tilted his head to the side to stare up at his brother, his long hair falling over his face. He huffed loudly, then let his head roll back to look at the ceiling again. "Nii-samaaaaaaaaaaa."

"Yes, Mokuba?"

"I think I'm _dying_."

"You are not dying."

"Why didn't you stop meeeeeeee."

Seto gave Mokuba a withering look, but stood up, stretching before leaving the room to get his idiot little brother some medicine.

"It's a good thing I love you," he grumbled under his breath. On the carpet behind him, Mokuba smiled.

* * *

 **Author's Notes** : oh man, when i wrote this originally like a month ago, this was the first time i'd ever referred to seto as "seto" and not "kaiba". it was so weird. to this day i still need to proofread carefully to make sure i dont accidentally call him "kaiba" in any of this fic's chapters.

thanks for reading!

–fearowkenya


	2. Mokuba Kaiba is up Way Past His Bedtime

**Chapter Summary:** Mokuba loved to catch Seto asleep. It wasn't because he felt reassured that his workaholic older brother was actually getting some rest for once. Okay, maybe it was, a little, but mostly, he found it hilarious.

 **Author's Notes:** i wrote this chapter right after i finished the noah arc in the anime. that arc was brutal, dude, and ugh i actually _cried_ when mokuba ran into setos arms and hugged him. these kids are tearing me apart

* * *

 **Mokuba Kaiba's Unremarkable Collection of Mundane Moments**

 **Chapter 2:** Mokuba Kaiba is up Way Past His Bedtime

Mokuba loved to catch Seto asleep.

It wasn't because he felt reassured that his workaholic older brother was actually getting some rest for once. Okay, maybe it was, a little, but mostly, he found it hilarious.

He peered around the edge of the door to Seto's study, a smile tugging at his lips when he caught sight of his brother slouched over his desk, head pillowed on his arms. Mokuba slipped into the room, inching toward the desk as quietly as he could. He came to a halt at his older brother's side, stifling a laugh.

Seto's head was turned to the side, his hair falling over his eyes, a few strands sticking up. His mouth was hanging open and he was drooling onto the sleeve of his shirt, as well as a small stack of papers sandwiched between his desk and his forearms. A loud snore erupted from his direction, shattering the silence and startling Mokuba, who immediately broke into a grin and smothered a giggle behind his hand.

His older brother was, without a doubt, the most unflattering sleeper he'd ever met. Still smiling, Mokuba leaned back against the wall, watching him. Who would ever believe that _the_ Seto Kaiba, top-tier duelist and president of the Kaiba Corporation, was so loud and slobbery and unsightly when he slept? Had he not seen it with his own eyes, thought Mokuba, he might not have believed it himself.

But here he was, bearing witness to the truth.

Mokuba watched him a while longer, then glanced at the clock that hung on the opposite wall. Quarter to four. He shifted his gaze back to his brother, crossing his arms over his chest. He had two choices: wake Seto up, or let him sleep.

The younger Kaiba bit his lip, weighing his options. Waking his brother up meant that he would probably resume his work, regardless of the fact that it was butts o'clock in the morning. Not only that, he'd probably scold Mokuba for being up so late and shoo him out of the study. What a hypocrite. He scowled at the thought.

On the other hand, if Mokuba were to leave him as he was and let him sleep, it would be highly probable that he'd wake up the following morning in a grumpy mood, neck and arms aching. Not to mention he'd drooled all over those documents on his desk, which may or may not have been important.

 _But at least he'd finally get some rest,_ whispered a tiny voice in the back of Mokuba's mind.

Finding himself nodding in agreement, Mokuba made his decision, but not before tiptoeing to the linen closet to fetch a thin blanket, throwing it over his older brother's shoulders before backing out of the study and returning to his own room.

* * *

 **Author's Notes** : mokuba kaiba is the most compassionate person i have ever seen, he just has so much empathy and understanding toward other people and i really admire that. in the sub version of the anime, at least. i hear he's a little more ruthless in the manga, but i haven't gotten around to reading that just yet.

thanks for reading!

–fearowkenya


	3. Mokuba Kaiba is Mildly Concerned

**Chapter Summary:** Seto gets his wisdom teeth pulled and Mokuba deals with the aftermath.

 **Author's Notes:** HEY HEY LISTEN HERE FOR A SECOND PLEASE! i just wanted to give you all a heads up and warn that there's some dentist-y stuff in this chapter, as well as a teeny tiny bit of blood. it's nothing explicit so i dont think i need to amp up the rating, but i just wanted to give everyone a warning, in case anyone is bothered by dentist-y stuff and/or blood! ok cool, as you were

* * *

 **Mokuba Kaiba's Unremarkable Collection of Mundane Moments**

 **Chapter 3** : Mokuba Kaiba is Mildly Concerned

Mokuba sighed as he turned the page of the magazine he was holding, then checked the time on his cell phone, which was balanced on his knee. Seto had talked about it so casually that morning, as though getting your wisdom teeth pulled was no big deal, but it had been over an hour since he'd last seen his brother. He wondered how much longer this would take.

"He should be done soon."

The younger Kaiba jumped, startled by the voice, then turned his head to look toward the front desk. The receptionist smiled at him.

"Oh, um. Thanks."

The waiting room fell into silence again, and Mokuba resumed flipping through the magazine in front of him. He stopped on a two-page spread of a chocolate parfait and paused to take a picture of the recipe with the camera on his phone, then closed the magazine and dropped it back onto the pile that sat on the waiting room table.

He leaned back against the couch in the waiting room, letting out a huge yawn. He idly wondered if he had time to take a nap, since this was taking _so long_ –

"Mokuba, it's time to go."

–never mind.

Seto strode into the room with a very determined look on his face, stopping by the armrest of the couch that the younger Kaiba sat on.

"Nii-sama!" Mokuba grinned, leaping to his feet. "How did it go?"

"I won, of course," replied his brother without missing a beat.

Mokuba stared at him, mouth hanging open in a mix of confusion and concern. Seto stared right back, face void of emotion. Mokuba's gaze shifted ever so slightly to the right, until he made eye contact with the receptionist.

"He's fine," she said.

* * *

Somewhere in the back of his mind, Mokuba knew that this would happen. He'd seen a few viral videos online of semi-conscious kids saying weird things after getting their wisdom teeth pulled, and heard a couple stories from his friends about their own personal experiences (his favorite was Mai's–she explained that in her post-anesthetic delirium she'd bought the entire cereal section of the local grocery store). It was only natural that his brother would also be in such a state.

He glanced at Seto, who sat next to him, glaring at the floor. He hadn't said a word since telling Mokuba that "he'd won". What had he won exactly? Mokuba thought about asking, but felt that it was probably better not to. Instead he had texted Isono, telling him to come pick them up–quickly.

Mokuba's phone vibrated. He looked at the screen. It was a reply from Isono, informing him that he would arrive with the car in ten minutes. He let out a tiny sigh of relief. Ten minutes, that wasn't so bad, they'd be home in no time–

His train of thought screeched to a halt when he saw Seto stand up and walk across the waiting room to the door.

"Nii-sama, _where_ are you _going_?" asked Mokuba, scrambling to his feet.

"Home," said Seto simply, turning the doorknob.

Mokuba grabbed his sleeve before he could take a step out the door. "Wait, hold on, we're like half an hour away from our house! By car! You can't just _walk_ back!"

The older Kaiba stopped in his tracks. "Oh."

Mokuba let his eyes slide shut for a moment, thankful that his brother didn't put up a fight. "Isono's coming to get us, we'll go home soon."

"Okay."

Mokuba guided him back to the couch on the other side of the waiting room. They sat down, and Seto resumed glaring at the floor. Scarcely a minute passed before he spoke again.

"Where's Isono?"

"Oh, um. He's not here yet."

He scoffed, eyes narrowing but remaining fixed on the floor. "Useless."

This was very weird, Mokuba thought, leaning forward to pick up another magazine from the pile on the table. He leafed through it absentmindedly, paying little attention to the words on the page in favor of continuously side-eyeing his older brother, who had shifted his attention from the floor to the door on the other side of the room.

"Where's Isono?" he asked again.

Mokuba blinked. "He's… not here yet, nii-sama."

Seto let out an impatient sigh, crossing his arms over his chest. "Useless!"

"C'mon nii-sama, it's been," he glanced down at his phone, "less than two minutes since you last asked. He'll be here soon."

Seto still didn't take his eyes off the door, and Mokuba felt that if he glared any harder, he would burn a hole right through it. He glanced at the receptionist again, who sat at the front desk watching them. She had a strained look on her face, as though she was trying very hard not to laugh. Normally, Mokuba would be pretty annoyed about that, but when Seto asked him for a _third_ time where Isono was, not even three minutes later, he decided he couldn't really blame her.

* * *

Unfortunately for Seto, when the car stopped, they were not yet home. He leaned over Mokuba to look out the window, squinting when he caught sight of the pharmacy outside.

"I don't live there," he said.

Mokuba choked back a giggle, turning it into a cough at the last second. "I know, nii-sama, we just have to go in real quick and pick up your painkillers."

Seto appeared to be genuinely confused and stared down at Mokuba, brows furrowed. "Painkillers? Why? I feel fine."

Eyes widening, Mokuba looked into the rearview mirror to share a look of disbelief with Isono, who shook his head, wearing the same expression as the younger Kaiba. Mokuba turned in his seat and put his hands on his older brother's shoulders, gazing deep into his bleary, unfocused eyes. "Shhh. Let's just go."

Reluctantly, Seto agreed, fumbling with his seatbelt and stepping out the door after Mokuba. The younger Kaiba had briefly considered locking him in the car, but decided that he would rather his older brother do and say bizarre things under close supervision.

As they made their way toward the pharmacy, Mokuba found himself looking over his shoulder several times to make sure that his brother was still following him. It was almost like he was the older, more responsible brother now.

… it was really weirding him out.

He slowed his pace, waiting for his older brother to catch up. "You all right, nii-sama?"

"I think somebody summoned scapegoats into my mouth."

"You know what? I'm sorry I asked," he gave his brother's arm a reassuring pat, then dragged him into the pharmacy.

When they arrived at the counter, the pharmacist informed them that they would have to wait a few minutes for the painkiller prescription to be filled. Which, at any other moment, Mokuba would have been perfectly okay with. However, in those few short minutes, Seto had managed to walk the perimeter of the store no less than eight times, looking angrier and angrier with each lap. Finally, after his ninth turn, he came to a stop next to Mokuba, letting out a huff of irritation.

Mokuba knew that he would regret it, but he asked anyway. "Nii-sama, what are you doing?"

His older brother remained silent, eyeing each aisle suspiciously.

"Uh… Nii-sama?"

"Where is Yuugi."

The conjunction of surprise and _total lack_ of surprise at the sentence that came out of his brother's mouth caught Mokuba so off guard that the only response he was able to give Seto was a very impassive "what".

 _"Where. Is. Yuugi."_

"I…" Mokuba was at a loss for words, "I don't–"

"I'm going to fight him." With that, Seto turned on his heel and stalked toward the shampoo aisle. Mokuba didn't have the heart to tell him that he wouldn't find Yuugi there.

* * *

By the time they finally made it home, Mokuba had heard much, much more about each and every dragon card in Seto's deck than he had ever anticipated. He was only half-listening to his brother prattle on about how beautiful and elegant Blue Eyes White Dragon was (for the third time) as they walked through the front door.

"Nii-sama, do you want something you eat? You haven't eaten anything all day, you must be _really_ hungry!" said Mokuba, a little too loudly, cutting his brother off before he could launch into a _very_ descriptive monologue of how exactly Different Dimension Dragon worked. Again.

Seto stopped mid-sentence, considering Mokuba's words for a moment, then shrugged. "It doesn't matter. I'll just get something when I get to the office."

Mokuba bit his lip, holding back an exasperated sigh. "Nii-sama, you aren't going to work today, you have to stay home and _rest_."

Seto scowled. "That's not happening."

"The only thing _not happening_ , is you going to work."

"Mokuba, don't be difficult."

" _You're_ the one being difficult!"

"No I'm not."

"Yes, you are."

" _No_ , I'm _not_!"

"See? You're being _super_ stubborn right now, probably because you're hungry, and, also I guess because you have four gaping holes in your mouth, anyway, sit down, I'll get you some yogurt or someth–"

"I don't have _time_ for yogurt!" he yelled, _"I have a company to run!"_

As the words left his mouth, so did a chunk of blood-soaked gauze. Mokuba and Seto watched in complete silence as it tumbled to the ground, landing on the expensive living room carpet. They stared at it for a long moment, then slowly looked toward one another.

"Okay," said Seto, so quietly that Mokuba barely heard him. He then sat directly on the floor.

* * *

Seto's head felt heavy and foggy when he woke up, and he quickly realized that he could not remember having fallen asleep. His mouth ached horribly, and he let out a groan of pain before rolling out of bed and and making his way to the door. He paused halfway down the hallway, trying to figure out how exactly he'd gotten from the dentist's office to his bedroom, but soon gave up, in too much pain to care. When he made it to the kitchen, he found that Mokuba was already there, sitting on the countertop and tapping away at his phone screen. He looked up when Seto entered the room.

"Nii-sama...?" he asked tentatively, "Are… are you… okay?"

"I feel like I got hit by a bus," grumbled Seto, yanking open the door to the pantry. "Where are my painkillers?"

"Second shelf, far left."

Seto mumbled a thanks, then crossed to the other side of the kitchen to get a glass of water. He stopped when he caught sight of his reflection in the kitchen window. His face was swollen to an almost comical degree, and he could see bruises starting to form along his jaw. "I look like hell."

"Well, yeah, you _did_ just come out of surgery."

He groaned again, swallowing the pills and draining his glass of water. "When did we get home? What time is it?"

Mokuba glanced at his phone again. "You've been out for like, six or seven hours."

"That answers neither of my questions, but all right," Seto turned his head, looking out into the living room. He squinted. "What is that on the floor?"

Mokuba hopped off the counter and padded across the kitchen to stand next to his brother. "Oh, that. That's your nasty bloody gauze that was in your mouth. I would have picked it up, but, that's gross, so no."

He stared at it for a moment longer, then looked down at Mokuba. "What… happened?"

The younger Kaiba stared at him blankly. "Wow. You really _don't_ remember anything."

"... Mokuba, what did I do?"

Mokuba moved to stand in front of Seto, standing on his tiptoes in attempt to put his hands on his brother's shoulders. He managed to reach his upper arms. "You're better off not knowing, nii-sama," he said with a grin, trying not to laugh at his older brother's alarmed expression, "But maybe I'll tell you someday."

* * *

 **Author's Notes:** fun fact, a lot of this is based on personal experience (i got my wisdom teeth out about three years ago) and i thought it would be cute and funny to put seto through the same thing but i got carried away and now i have 2k words of mokuba dealing with post-anesthetic seto. im sorry mokuba.

actually, it's pretty ironic, because about a month after i posted this chapter on ao3, i went to the dentist and found out that i had somehow managed to grow a _fifth_ wisdom tooth. isnt that amazing. seto kaiba predicting my future. thanks pal

thanks for reading!

–fearowkenya


	4. Mokuba Kaiba has a Snacktime Struggle

**Chapter Summary:** Mokuba goes downstairs at one in the morning to get a midnight snack. What could possibly go wrong?

 **Author's Notes:** yesterday i was up watching the orichalcos arc until FOUR IN THE MORNING i thought i was GOING TO DIE

* * *

 **Mokuba Kaiba's Unremarkable Collection of Mundane Moments**

 **Chapter 4:** Mokuba Kaiba has a Snacktime Struggle

Mokuba lay awake in his bedroom at half past midnight, staring at the ceiling with only one thing in mind: the last chocolate chip cookie. It was alone in a tin, nestled in some wax paper, at the very back of the fridge downstairs in the kitchen. It was the last of its kind, the only remaining cookie from the batch he'd made today with some of his friends.

A smile spread across his face as he recalled the day's events, remembering when Anzu placed the dark blue tin in his hands before gently dusting some flour off of his face. That had been a good day. An _excellent_ day, even. They'd–he was unable to stifle a giggle–they'd all gone to Otogi's house, armed to the teeth with cookie-making ingredients. The recipe that Yuugi had chosen only accounted for about two dozen cookies, which was _not quite_ enough to sustain a pack of seven very hungry teenagers (and one preteen).

To make a long story short, Ryou had suggested that they just double all of the ingredients in the recipe, a seemingly foolproof plan, but–Mokuba laughed alone in the darkness of his room–but somehow, _somehow_ , Honda had messed up the math and they'd ended up with not four, not five, not even _six_ or _seven_ batches of cookies, but _eight_.

After the uproar died down–" _Ninety-six cookies,_ " Otogi had wheezed, laughing so hard he was doubled over in pain, leaning heavily on Jounouchi (who was also laughing, tears pouring down his face) to keep himself standing, " _Ninety-six **goddamn** cookies!_ "–Shizuka pointed out that maybe this was for the best: this way, everyone would be able to take some cookies home!

...And that's how he'd ended up with an entire tin of chocolate chip cookies all to himself.

The first thing he'd done when he'd gotten home, of course, was share them with his older brother. Seto was as stubborn as ever, narrowing his eyes when Mokuba explained where the cookies came from, but agreed to take one from the tin when he learned that Mokuba had a hand in making them. As Mokuba expected, Seto showed no outward reaction upon trying one, but judging by how fast the number of cookies plummeted afterwards, it was safe to assume that he liked them. Just thinking about it brought a soft smile to Mokuba's face. Small victories.

Anyway, he thought to himself, blinking once to rearrange his thoughts, when he turned in for the night, there had only been a single cookie left, and now, at quarter to one in the morning, it was calling out to him. And he intended to heed its call.

He tiptoed out of his room and down the hall, the floor freezing cold beneath his bare feet. The house was completely silent, eerily so. Mokuba couldn't even hear the familiar tapping sound of his brother typing on his computer, and when he passed by Seto's study, the lights were off. Odd, thought Mokuba, normally his brother was still awake at this time. He shrugged it off, assuming (hoping...?) that Seto had just gone to sleep early for once. Good. He needed it.

Nodding to himself, Mokuba picked up the pace, turning the corner to go down the stairs. He paused, foot hovering over the second to last step–it would creak loudly under his weight–before soundlessly hopping over it to the floor. Grinning, he crossed through the living room to go into the kitchen with a spring in his step. He would be in and out in two seconds flat and back upstairs in his room without making a sound, that last delicious cookie clamped between his teeth. Mokuba had to admit, he was pretty darn good at sneaking around so quietly, and he dared say that there wasn't a single person on earth better at it than himse–

Mokuba froze mid-step, his inner monologue coming to an abrupt end. He peered around the doorframe, squinting at the sight of a dim light coming from the kitchen. The fridge light, he realized, eyes widening, _his cookie…!_

Sure enough, the familiar clank of the lid coming off the cookie tin rang out, echoing loudly throughout the room. He heard the wax paper rustle inside the tin, someone was going to _steal_ his cookie _this is just NOT going to happen–!_

Mokuba was not sure who exactly he expected to see when he marched into the kitchen, frown on his face and hands curled into fists at his sides, but it was certainly _not_ his older brother.

In hindsight, there was really no one else it could have been, but with his cookie in mortal peril, Mokuba hadn't really given it much thought. So when his eyes adjusted to the darkness of the kitchen, his mouth fell open in surprise. There he was, Seto Kaiba, in all of his grandeur, standing in front of the open fridge, literally and proverbially caught with his hand in the cookie jar.

He was wearing those awful pajamas, Mokuba noticed, the super-old faded blue ones that he'd long since outgrown but was too busy to remember to replace. He looked so _silly_ in them, mostly because the bottom hem of the legs were a good three or four inches higher than they should've been. Mokuba remembered when Seto had been shorter and the excess fabric would drag on the ground, but now it was way above his ankles. At least he didn't have that horrible button-up shirt that went with it anymore, god, it barely even cl–

 _–wait. Cookie. Priorities, Mokuba._

"Nii-sama, hello," he said in a soft, sweet voice, calling forth the fakest angelic smile he could muster, "Whatcha got there?"

Seto remained expressionless, gaze shifting from the cookie to his younger brother. He said nothing.

"Is that, maybe," Mokuba paused, taking one step closer, "I dunno, _my_ cookie?"

For a while, Seto was quiet, watching carefully as Mokuba approached him, waiting until he was less than an arm's length away to respond.

"It's mine, now."

His words were so faint that the younger Kaiba scarcely heard them, but the moment he did, Mokuba let out an indignant sound somewhere between a gasp and a shriek and lunged forward, only to be met with thin air as Seto raised his arm way above Mokuba's head, _that's not fair, nii-sama, you're way taller…!_

Mokuba stuck his lip out in a pout, shoulders slouched in defeat, and _yes_ , it _worked_ , Seto smirked at him and relaxed, arm lowering _just enough_ to–

"Gotcha!"

Mokuba jumped and grabbed his brother's hand, his weight dragging Seto's arm down–and the cookie with it. He knew he could never wrestle it out of his brother's grip, Seto was too strong, but it was within his reach... so he did the only thing he could think of to turn the situation around, and leaned forward and _licked the cookie_.

Mokuba returned Seto's disgruntled, mildly disdainful look with a devilish grin, releasing his hold on his brother's arm and stepping back, leaning against the fridge.

"I claimed it," he said proudly, tilting his chin up, "I licked it, so it's _mine_."

Seto glared down at him, cookie still in his hand. Mokuba waited for his older brother to scoff and look away before reluctantly giving up the cookie, but…

A tiny smile tugged at the corner of Seto's lips. He gave Mokuba an indifferent shrug, and instead of reaching down to hand the cookie over to his younger brother–

Mokuba's jaw dropped.

–he ate it himself.

 _"EWWWWWWWWWWW–!"_

Seto turned away from Mokuba, his younger brother's disgusted screeching drowning out the muffled, almost inaudible laugh he let out as he left the room.

* * *

 **Author's Notes:** important company owner or not, seto kaiba is still a gross teenage boy who is undeterred by little brother germs :') better luck next time, mokuba!

even though it was only a few paragraphs, it was super refreshing to write about mokuba interacting with people who arent kaiba. dont get me wrong, their relationship is one of my favorites ever but it's nice to see mokuba socializing with other people too. im sort of tempted to write the entire cookie-making disaster as its own fic but idk, we'll see

anyway, before i can even think about doing that, i have to work on the next chapter for this. i have a few more ideas for chapters but i somehow ended up writing a super long fic about insector haga and dinosaur ryuzaki, so lately i've been working on that instead. i really like how it's turning out though, so i hope you'll give it a chance when i do get around to posting it.

one last thing! shoutout to my anonymous/guest reviewer for leaving a super sweet review on chapter 3! i appreciate it! i'd reply privately but, yknow, anon stuff, so yeah! thank you!

thanks for reading!

–fearowkenya


	5. Mokuba Kaiba is Very Confused

**Chapter Summary:** Mokuba does the impossible and forgets his own birthday. He also nearly falls down the stairs.

 **Author's Notes:** AW MAN, i'm a little over two hours late in my own time zone but im sure it's still mokuba's birthday somewhere on this planet.

* * *

 **Mokuba Kaiba's Unremarkable Collection of Mundane Moments**

 **Chapter 5:** Mokuba Kaiba is Very Confused

It was the sunlight streaming through the windows that woke Mokuba up that morning. His eyes fluttered open, then snapped shut again at the overpowering brightness coming in from outside.

He made an indistinct grumbling sound, then rolled over, settling down again and tugging his blankets closer. Stupid freakin' sun, he thought to himself, what's its deal?! It wasn't usually _this_ bad before he had to get up for work–

Mokuba gasped, bolting upright.

"What time is it?!" he shouted at his empty room, jumping out of bed and swiping his cell phone off his bedside table. He jammed the home button over and over until the screen lit up, then said a few very rude words that boys his age were not supposed to say.

 _ **11:47am.**_

"I'm _late_!" he screeched to himself, running over to his dresser and yanking the drawers open, rummaging through them for his clothes–he didn't _care_ which ones, oh _man_ he was _so late_! He changed out of his pajamas at a speed that was surely a world record before rocketing out of his room and tearing down the hall.

"How did this happen?! Why didn't my alarm go off?!" he hissed under his breath as he barreled down the stairs. He opened the alarm clock app on his phone, only to find that his everyday 7am alarm had been switched off, "What the _hell_?!"

He was so busy gaping at the screen that he missed the last stair and went tumbling forward. He braced himself for a nasty fall, but it never happened.

"Be careful, Mokuba-sama," came Isono's voice, "I wouldn't want you to get hurt, today of all days."

"Huh?" Mokuba cracked his eyes open and found himself safely in Isono's grip. "Oh, uh, thanks, Isono."

"Of course," Isono replied, setting him down and giving him a polite nod, "Have a good day, Mokuba-sama!"

Mokuba watched him go, eyes wide with confusion.

"W-wait, Isono, where are you going?"

Isono didn't even stop walking. "I've just finished running an errand for Seto-sama," he said, tucking a thick stack of important-looking documents under his arm, "and now my presence is requested at the Kaiba Corporation main office. Fuguta has been holding down the fort for me, but it's a big job for only one person. I'll see you tomorrow, Mokuba-sama."

"Hold on, that's also–" Isono closed the front door behind him, cutting Mokuba off mid-sentence, "–where… I'm going…?"

Mokuba stood at the bottom of the stairs for a few seconds, staring blankly at the empty space where Isono had previously been standing, questions racing through his mind. _Running an errand?_ _What_ errand? And why _here_ , in the _house_?! It was almost noon! Shouldn't everyone have been at the office already? Why was Fuguta _alone_ over there? What on _earth_ was going on?!

"...today of all days…?" Mokuba echoed Isono's words. He blinked, trying to remember if there was something unusual happening today. He'd checked the Kaiba Corporation event calendar at the beginning of the week, but he hadn't noticed anything out of the ordinary...

Wait.

Mokuba glanced at his phone again, then let out a startled laugh.

July 7th.

He shook his head, amazed at himself. He had always been skeptical that a person could forget their own birthday; it seemed like such an impossible thing to lose track of, but now he'd gone and done it himself!

"'Cause I was in such a rush this morning..." he murmured to himself, unable to keep a smile off his face.

Mokuba's smile faded. It being his birthday didn't change the fact that he was very, _very_ late for work; he still had important vice-president stuff to do, and he didn't even have a ride to the Kaiba Corporation office building. He hoped his brother wouldn't be _too_ upset… He leaned against the banister and typed out a quick text message to Seto.

 _ **11:52AM**_ _[nii-sama my alarm didnt go off, idk why, but everyone left w/o me and isono was just here but he didnt even take me with him! how come no one woke me up?]_

He sighed, letting go of the railing at the bottom of the stairs and drifting off toward the kitchen. Seto was always so busy, it would probably be at _least_ fifteen minutes before–

 _BZZT! BZZT!_

Mokuba stopped in his tracks. That sounded like Seto's phone's text tone, but how could that be? His brother would have gone to work hours ago. Could he have forgotten his cell phone at home?

He didn't have time to finish thinking about it, because his own phone vibrated.

 _ **11:53AM**_ _[I disabled your alarm.]_

Mokuba blinked down at his screen. "Wha…?" He tore his gaze away from the screen and made his way to the kitchen, confusion and anticipation swirling around in his chest. When he arrived, Seto was waiting for him, leaning against the counter by the fridge. Mokuba noticed that he was dressed in his casual clothes, not his work ones.

"Nii-sama…" he said, slowly stepping into the kitchen, "Why did you disable my alarm? And when?"

"Last night, before you went to bed. I wanted you to sleep in," Seto replied, as though that answered everything. Mokuba's lack of response prompted him to continue talking, "You're taking the day off today. You know. Because it's your birthday."

Mokuba smiled, tucking a strand of hair behind his ear. "Aww, nii-sama, thanks…" he said. Then he frowned, "Wait, then how come _you're_ still here? Shouldn't you be at work?"

Seto didn't answer for a moment. When he finally did, he looked away from Mokuba, finding a spot on the wall to stare at instead. "I had Isono bring me all the necessary paperwork I had to take care of today," he said, idly tapping a pile of empty file folders lying in a heap on the counter next to him, "Thankfully, you slept long enough for me to get it all done. Isono and Fuguta can handle the rest."

Mokuba continued to stare at his brother, his eyes growing wider and wide as the meaning behind his brother's words became clear.

Seto fidgeted with the edge of his jacket, then shifted his gaze back to Mokuba. "In other words, I'm… also taking the day off. To spend with you. Unless you have other plans, that is–"

Mokuba rushed forward, tackling his older brother in a hug. Seto allowed himself to smile, resting his hands on Mokuba's shoulders.

"I take it you don't have any other plans, then?"

Mokuba shook his head.

"Good. Now tell me. Where can we go to get you a chocolate parfait? If I'm going to take the day off, I might as well spoil you."

"Dessert for breakfast? Nii-sama, you're _horrible_." But Mokuba was grinning. "I have a few places in mind. Maybe we could try one from each?"

Seto smirked at him. "Don't push your luck," he said, but his tone was gentle, "We'll get going as soon as you go get changed."

Mokuba looked up at him, eyes narrowed. "What? Why?"

"Your shirt's on backwards. And I'm pretty sure those jeans are inside out."

Mokuba looked down at himself, jaw dropping. Sure enough, Seto was right. His face reddened, and he glared back up at his brother, who was trying in vain to hide a smile behind his hand.

"Be right back," Mokuba grumbled, leaving the kitchen to fix his disastrous outfit. When he returned, his brother was still in the same place he left him.

Seto smirked again. "Ready to go? Are you sure you have your shirt on right this time?"

Mokuba scoffed, following his brother out of the kitchen toward the front entrance. "Hey, I was in a hurry."

"In a hurry to nearly fall down the stairs, apparently."

"What? You know about _that_ too? Geez. I can't catch a break in this house." Mokuba tried to fake a pout, but his laughter broke through, his smile springing back onto his face when he grabbed his brother's hand, lacing their fingers together as they stepped out the door.

* * *

 **Author's Notes:** happy birthday mokuba my darling my angel my honey nut cheerio i love you so much youre the best B)

ive learned that writing seto in kinda emotional/heartfelt situations is pretty tough. i think he still probably has trouble getting his feelings across, and its kind of hard for me to describe that, but i enjoyed the challenge.

oh yeah, i recently made a new twitter account exclusively for my yugioh rambling and headcanons. my username is kaibacorn if you ever feel like dropping by! that is kaibaCORN as in, the vegetable. why? honestly i dont know. it was a friend's idea

thanks for reading!

–fearowkenya


	6. Mokuba Kaiba is Super Sneaky

**Chapter Summary:** Mokuba decides he wants to try drinking coffee. Seto doesn't understand why.

 **Author's Notes** : ive been sitting on this idea for AGES and im so glad i finally wrote it out

* * *

 **Mokuba Kaiba's Unremarkable Collection of Mundane Moments**

 **Chapter 6:** Mokuba Kaiba is Super Sneaky

"Hey nii-sama, let me try your coffee."

Startled by the sound of his younger brother's voice, Seto nearly dropped his coffee cup on himself. The coffee itself sloshed around in the mug, coming dangerously close to spilling over the edge.

Sighing, the older Kaiba set the cup down on the kitchen counter and turned to see his little brother sitting innocently on the kitchen island, feet dangling off the edge.

"Mokuba," he said evenly, "Good morning. I didn't hear you come in."

Mokuba grinned. "Nii-sama, you're like, barely alive first thing in the morning, especially when you do _stupid things_ including but not limited to staying up until four in the morning and waking up at quarter past six. Both of which you've done twice in the past two days. I don't think you'd have noticed _a herd of elephants_ if they went stampeding through the kitchen. Not until you've had your coffee, at least. Which brings me back to the first thing: nii-sama, let me try your coffee."

Seto frowned, picking his mug up again and taking a sip. It burned his tongue. He took a second sip anyway. "Did you run out of orange juice?"

"Huh? Oh, nah," said Mokuba, hopping off the kitchen island to the floor, "We have plenty. I just wanna try your coffee."

"Why?"

He shrugged. "I dunno. Just wanna."

"Just yesterday you suggested that I should "stop drinking so much of this stuff" and that if I "turned out to be a caffeine-addict" and "ruined my teeth" it would be "my own fault"."

"Maybe _I_ also want to be a caffeine addict. Did you consider that, brother dearest?"

Seto scoffed. "That is without a doubt the worst argument I have ever heard."

"Cool," said Mokuba, shrugging, "Give me your coffee."

"I could just buy you a hot chocolate on the way to the office instead."

"Sure, but coffee first."

"There is absolutely no point to this," said Seto, crossing his arms, "You're going to hate it."

"How do you know that?" said Mokuba, tilting his chin up in defiance, "Who knows, maybe I'll _love_ it. Gimme."

Seto stared down at him. "Mokuba, I'm telling you, you're going to hate it."

Mokuba ignored him and held his hands out. Rolling his eyes, Seto handed his younger brother the coffee cup. Mokuba took a huge swig of Seto's coffee, not even flinching at how hot it was. He swallowed it, then stared at Seto for a solid ten seconds, expressionless, before finally speaking.

"Wow, nii-sama, that tasted awful, I hated it," he deadpanned, "Why would you even let me drink this?"

"Mokuba, that's exactly what I—"

"Just messin' with you, nii-sama." Mokuba broke into a grin and took another sip. He gagged, "Actually, no I'm not, this stuff is _terrible_ , do you not even put sugar in it? Cream? Why do you hate yourself? Why do you hate _me_?"

"It's an acquired taste, it's not so bad after a while."

Mokuba shoved the cup back into Seto's hands. "Well, you go ahead and acquire that taste, then. It's all yours, nii-sama. Okay, let's go get hot chocolate."

With that, Mokuba turned on his heel and raced up the stairs to get his jacket. Seto watched him go, lifting the cup to his lips to finish his coffee, then frowned and pulled the mug away from his face. He peered down into it.

Empty.

" _Unbelievable_."

"What was that, nii-sama?" Mokuba stood at the foot of the stairs waiting for him, smug smirk on his face.

"Nothing," Seto replied, turning his back to Mokuba to put his empty mug in the sink (and hide the tiny smile that tugged at the corner of his mouth), "Let's go get you a hot chocolate."

* * *

 **Author's Notes:** hello everyone, its certainly been a while since ive update this fic. i hope youve all been well and i hope you enjoyed the chapter! now im gonna do a bit of shameless self-promotion: i'm writing a ygo fic that is an animorphs AU titled "escafil", and i've been working suuuuuper hard on it! if any of you are feeling up to it, it would mean a whole lot to me if you could check it out. you dont have to know anything about animorphs to read it! if its not your thing, thats ok! but ive put tons of effort into it, probably more than any other fic ive ever written, so i'd really appreciate you taking a look if you have the chance and/or feel like it. thank you!

in other news, i finally finished the duel monsters anime and im dead inside. how am i ever going to recover from this pain (im not. im going to read the manga next, because i obviously hate being happy)

thanks for reading!

-fearowkenya


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